210 research outputs found

    Molecular mechanisms of neurogenic aging in the adult mouse subventricular zone

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    In the adult rodent brain, the continuous production of new neurons by neural stem/progenitor cells (NSPCs) residing in specialized neurogenic niches and their subsequent integration into pre-existing cerebral circuitries supports odour discrimination, spatial learning, and contextual memory capabilities. Aging is recognized as the most potent negative regulator of adult neurogenesis. The neurogenic process markedly declines in the aged brain, due to the reduction of the NSPC pool and the functional impairment of the remaining NSPCs. This decline has been linked to the progressive cognitive deficits of elderly individuals and it may also be involved in the onset/progression of neurological disorders. Since the human lifespan has been dramatically extended, the incidence of age-associated neuropsychiatric conditions in the human population has increased. This has prompted efforts to shed light on the mechanisms underpinning the age-related decline of adult neurogenesis, whose knowledge may foster therapeutic approaches to prevent or delay cognitive alterations in elderly patients. In this review, we summarize recent progress in elucidating the molecular causes of neurogenic aging in the most abundant NSPC niche of the adult mouse brain: the subventricular zone (SVZ). We discuss the age-associated changes occurring both in the intrinsic NSPC molecular networks and in the extrinsic signalling pathways acting in the complex environment of the SVZ niche, and how all these changes may steer young NSPCs towards an aged phenotype

    Extracellular vesicle-induced differentiation of neural stem progenitor cells

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    Neural stem progenitor cells (NSPCs) from E13.5 mouse embryos can be maintained in culture under proliferating conditions. Upon growth-factor removal, they may differentiate toward either neuronal or glial phenotypes or both. Exosomes are small extracellular vesicles that are part of the cell secretome; they may contain and deliver both proteins and genetic material and thus play a role in cell–cell communication, guide axonal growth, modulate synaptic activity and regulate peripheral nerve regeneration. In this work, we were interested in determining whether NSPCs and their progeny can produce and secrete extracellular vesicles (EVs) and if their content can affect cell differentiation. Our results indicate that cultured NSPCs produce and secrete EVs both under proliferating conditions and after differentiation. Treatment of proliferating NSPCs with EVs derived from differentiated NSPCs triggers cell differentiation in a dose-dependent manner, as demonstrated by glial-and neuronal-marker expression

    Las cuentas por cobrar comerciales y su influencia en la liquidez de la Empresa Telefónica del Perú S.A.A., 2010-2018

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    El trabajo de “investigación titulado Las Cuentas por Cobrar Comerciales y su influencia en la Liquidez de la empresa Telefónica del Perú S.A.A, está orientado a un análisis exhaustivo siendo las cuentas por cobrar el principal activo de la empresa lo cual constituye un factor importante al momento de establecer deficiencias en el otorgamiento de créditos. Para el desarrollo de la investigación se ha utilizado diferentes instrumentos metodológicos, técnicas y procedimientos, tales como: método analítico, histórico y documental, que permitió determinar la relación con la liquidez en la empresa; con el objetivo de determinar en qué medida las cuentas por cobrar comerciales afectan la liquidez de la empresa. Por último, se concluye que existe relación entre las cuentas por cobrar comerciales y la liquidez de la empresa Telefónica del Perú S.A.A 2010-2018.Tesi

    Molecular signatures of the aging brain: finding the links between genes and phenotypes

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    Aging is associated with cognitive decline and increased vulnerability to neurodegenerative diseases. The progressive extension of the average human lifespan is bound to lead to a corresponding increase in the fraction of cognitively impaired elderly individuals among the human population, with an enormous societal and economic burden. At the cellular and tissue levels, cognitive decline is linked to a reduction in specific neuronal subpopulations, a widespread decrease in synaptic plasticity and an increase in neuroinflammation due to an enhanced activation of astrocytes and microglia, but the molecular mechanisms underlying these functional changes during normal aging and in neuropathological conditions remain poorly understood. In this review, we summarize very recent and outstanding progress in elucidating the molecular changes associated with cognitive decline through the genome-wide profiling of aging brain cells at different molecular levels (genomic, epigenomic, transcriptomic, proteomic). We discuss how the correlation of different molecular and phenotypic traits driven by mathematical and computational analyses of large datasets has led to the prediction of key molecular nodes of neurodegenerative pathways, and provide a few examples of candidate regulators of cognitive decline identified with these approaches. Furthermore, we highlight the dysregulation of the synaptic transcriptome in neuronal cells and of the inflammatory transcriptome in glial cells as some of the key events during normal and neuropathological human brain aging

    Neuroserpin polymers cause oxidative stress in a neuronal model of the dementia FENIB

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    The serpinopathies are human pathologies caused by mutations that promote polymerisation and intracellular deposition of proteins of the serpin superfamily, leading to a poorly understood cell toxicity. The dementia FENIB is caused by polymerisation of the neuronal serpin neuroserpin (NS) within the endoplasmic reticulum (ER) of neurons. With the aim of understanding the toxicity due to intracellular accumulation of neuroserpin polymers, we have generated transgenic neural progenitor cell (NPC) cultures from mouse foetal cerebral cortex, stably expressing the control protein GFP (green fluorescent protein), or human wild type, G392E or delta NS. We have characterised these cell lines in the proliferative state and after differentiation to neurons. Our results show that G392E NS formed polymers that were mostly retained within the ER, while wild type NS was correctly secreted as a monomeric protein into the culture medium. Delta NS was absent at steady state due to its rapid degradation, but it was easily detected upon proteasomal block. Looking at their intracellular distribution, wild type NS was found in partial co-localisation with ER and Golgi markers, while G392E NS was localised within the ER only. Furthermore, polymers of NS were detected by ELISA and immunofluorescence in neurons expressing the mutant but not the wild type protein. We used control GFP and G392E NPCs differentiated to neurons to investigate which cellular pathways were modulated by intracellular polymers by performing RNA sequencing. We identified 747 genes with a significant upregulation (623) or downregulation (124) in G392E NS-expressing cells, and we focused our attention on several genes involved in the defence against oxidative stress that were up-regulated in cells expressing G392E NS (Aldh1b1, Apoe, Gpx1, Gstm1, Prdx6, Scara3, Sod2). Inhibition of intracellular anti-oxidants by specific pharmacological reagents uncovered the damaging effects of NS polymers. Our results support a role for oxidative stress in the cellular toxicity underlying the neurodegenerative dementia FENIB

    Cryptosporidium Oocyst Contamination in Drinking Water: A Case Study in Italy

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    The aim of this study was to evaluate the occurrence of Cryptosporidium oocysts in a drinking water treatment plant (DWTP) located in a rural area of northern Italy. Influent and effluent samples were collected at the DWTP over three years (2013–2016). In parallel, tap water samples from a public drinking fountain were collected as well. All samples were analyzed for the presence of Cryptosporidium spp. oocysts by a common method based on an immunomagnetic separation (IMS)/immunofluorescence assay (IFA), complemented by 4,6-diamidino-2-phenylindole (DAPI) staining. A reverse transcriptase-PCR (RT-PCR) protocol was added to evaluate oocyst viability. The results highlighted a high variability of oocyst concentrations across all samples (mean 4.3 ± 5.8/100 L) and a high variability in the percentage of DAPI-positive specimens (mean 48.2% ± 40.3%). Conversely, RT-PCR did not reveal the presence of viable C. parvum and C. hominis oocysts. A nested PCR targeting Cryptosporidium 18S ribosomal DNA, carried out in two water samples, confirmed the presence of a Cryptosporidium genotype associated with wild animals in the river and in tap water. The results obtained underline the vulnerability of the investigated surface water to Cryptosporidium spp. contamination. Although the recovered Cryptosporidium genotype is not a human pathogen, its presence demonstrates the existence of a potential pathogen Cryptosporidium spp. contamination risk. Moreover, these results underline the importance of also considering unconventional (not bacterial) biological contaminations (protozoa) in water resources in rural areas, including those of developed countries

    Pengaruh Pemberian Bunga Rosella Terhadap Perubahan Tekanan Darah Penderita Hipertensi Dengan Terapi Captopril Di Desa Kamiwangi Kecamatan Toili Barat Kabupaten Luwuk Banggai

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    Hypertension is a cardiovasculer disturbance which is mostly founded in society. in healing hypertension, it needs continually Treatments. Rosella flower is a plant that has many good Components to heal hypertension. This research uses Quasy experiment design with control group. the amout of population in this research are 40 people. The method in taking sample uses purposive sampling and it got 30 respondents as the sample. The information of blood pressure was taken from the clients by using spygmomanometer, then it was displayed in table and processed by using SPSS program (statistic program for society science), used coupling T test, uncoupling T test with interpretation level 95%(a<0.05). The result of the research shows that the hypertension patients with captopril therapy which were given boiled dry rosella, got faster reduction of blood pressure after 2 hours than the hypertension patients with only captopril therapy. By using coupling T test, p-value was 0,00 . With mean value of the difference of reduction of sistolik blood pressure on the first day in intervention group was 28 mmHg while the control group was 11mmHg. on the second day, the reduction of sistolik blood pressure in intervention group was 13,33 l, and for control group, it was 5 mmHg. The diastolic blood pressure on the first day, the mean of the reduction of blood pressure in intervention group was 14mmHg while in control group was 6mmHg. On the second day, the mean of sistolic blood pressure in intervention group was 6 mmHg, and 2mmHg for control group. Key words: hypertension, rosella flower, captopril therapy Hipertensi merupakan penyakit gangguan kardiovaskuler. Bunga rosella adalah tumbuhan herbal untuk mengobati hipertensi. Tujuan penelitian melihat pengaruh bunga rosella terhadap tekanan darah penderita hipertensi dengan terapi captopril. Metode : quasi eksperiment design with control group, purposive sampling, 30 subyek (15 kelompok intervensi, 15 kelompok kontrol). Intervensi, subyek dengan captopril ditambahkan seduhan kering bunga rosella. Kontrol subyek mendapatkan dengan captopril saja. Sistolik pre kelompok intervensi, pada kategori hipertensi grade I, II, III. Sistolik post masuk pada kategori normal, pre hipertensi, hipertensi grade I, II, III. Diastolik pre kelompok intervensi terbesar kategori pre hipertensi, post diastolik terbesar berada pada kategori normal. Kelompok kontrol sistolik pre terbesar pada hipertensi grade II, post berada pada hipertensi grade I. Diastolik kelompok kontrol pre terbesar pada hipertensi grade I, post terbesar hipertensi grade I. Dianalisis dengan uji T berpasangan, dan uji T tidak berpasangan, α ≤ 0,05. Hasil Uji T berpasangan tekanan darah pre-post sistolik p-value 0,000, diastolik p-value 0,004, didapatkan pengaruh bunga rosella terhadap penderita hipertensi dengan captopril, penurunan tekanan darah kelompok intervensi sistolik 19,333, diastolik 10,000 mmHg, kelompok kontrol sistolik 9,000 mmHg, diastolik 4,333 mmHg. Hasil Uji T tidak berpasangan di dapatkan perbedaan penurunan tekanan darah kelompok intervensi lebih besar dibadingkan kelompok kontrol, dengan p-value, sistolik 0,000, diastolik 0,025. Perbedaan penurunan sistolik sebesar 12,333 mmHg, diastolik 6,333 mmHg. Kesimpulan didapatkan pengaruh pemberian bunga rosella terhadap Perubahan tekanan darah penderita hipertensi dengan terapi captopri

    Cul3 regulates cytoskeleton protein homeostasis and cell migration during a critical window of brain development

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    De novo loss of function mutations in the ubiquitin ligase-encoding gene Cullin3 (CUL3) lead to autism spectrum disorder (ASD). Here, we used Cul3 mouse models to evaluate the consequences of Cul3 mutations in vivo. Our results show that Cul3 haploinsufficient mice exhibit deficits in motor coordination as well as ASD-relevant social and cognitive impairments. Cul3 mutant brain displays cortical lamination abnormalities due to defective neuronal migration and reduced numbers of excitatory and inhibitory neurons. In line with the observed abnormal columnar organization, Cul3 haploinsufficiency is associated with decreased spontaneous excitatory and inhibitory activity in the cortex. At the molecular level, employing a quantitative proteomic approach, we show that Cul3 regulates cytoskeletal and adhesion protein abundance in mouse embryos. Abnormal regulation of cytoskeletal proteins in Cul3 mutant neuronal cells results in atypical organization of the actin mesh at the cell leading edge, likely causing the observed migration deficits. In contrast to these important functions early in development, Cul3 deficiency appears less relevant at adult stages. In fact, induction of Cul3 haploinsufficiency in adult mice does not result in the behavioral defects observed in constitutive Cul3 haploinsufficient animals. Taken together, our data indicate that Cul3 has a critical role in the regulation of cytoskeletal proteins and neuronal migration and that ASD-associated defects and behavioral abnormalities are primarily due to Cul3 functions at early developmental stages

    Molecular profiling of aged neural progenitors identifies Dbx2 as a candidate regulator of age-associated neurogenic decline.

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    Adult neurogenesis declines with aging due to the depletion and functional impairment of neural stem/progenitor cells (NSPCs). An improved understanding of the underlying mechanisms that drive age-associated neurogenic deficiency could lead to the development of strategies to alleviate cognitive impairment and facilitate neuroregeneration. An essential step towards this aim is to investigate the molecular changes that occur in NSPC aging on a genomewide scale. In this study, we compare the transcriptional, histone methylation and DNA methylation signatures of NSPCs derived from the subventricular zone (SVZ) of young adult (3 months old) and aged (18 months old) mice. Surprisingly, the transcriptional and epigenomic profiles of SVZ-derived NSPCs are largely unchanged in aged cells. Despite the global similarities, we detect robust age-dependent changes at several hundred genes and regulatory elements, thereby identifying putative regulators of neurogenic decline. Within this list, the homeobox gene Dbx2 is upregulated in vitro and in vivo, and its promoter region has altered histone and DNA methylation levels, in aged NSPCs. Using functional in vitro assays, we show that elevated Dbx2 expression in young adult NSPCs promotes age-related phenotypes, including the reduced proliferation of NSPC cultures and the altered transcript levels of age-associated regulators of NSPC proliferation and differentiation. Depleting Dbx2 in aged NSPCs caused the reverse gene expression changes. Taken together, these results provide new insights into the molecular programmes that are affected during mouse NSPC aging, and uncover a new functional role for Dbx2 in promoting age-related neurogenic decline.This work was supported by grants to P.J.R.-G. from the 6 Wellcome Trust (WT093736) and the BBSRC (BB/P013406/1, BB/M022285/1), by funding from 7 Sapienza University of Rome (G.L, S.B., E.C) and by a grant from the Spanish Ministry of 8 Economy to P.B. (BFU2016-75412-R, co-financed by FEDER). The Babraham Institute Biological 9 Services Unit is supported by Campus Capability Grant funding from the BBSRC

    Polymerogenic neuroserpin causes mitochondrial alterations and activates NFκB but not the UPR in a neuronal model of neurodegeneration FENIB

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    The neurodegenerative condition FENIB (familiar encephalopathy with neuroserpin inclusion bodies) is caused by heterozygous expression of polymerogenic mutant neuroserpin (NS), with polymer deposition within the endoplasmic reticulum (ER) of neurons. We generated transgenic neural progenitor cells (NPCs) from mouse fetal cerebral cortex stably expressing either the control protein GFP or human wild type, polymerogenic G392E or truncated (delta) NS. This cellular model makes it possible to study the toxicity of polymerogenic NS in the appropriated cell type by in vitro differentiation to neurons. Our previous work showed that expression of G392E NS in differentiated NPCs induced an adaptive response through the upregulation of several genes involved in the defence against oxidative stress, and that pharmacological reduction of the antioxidant defences by drug treatments rendered G392E NS neurons more susceptible to apoptosis than control neurons. In this study, we assessed mitochondrial distribution and found a higher percentage of perinuclear localisation in G392E NS neurons, particularly in those containing polymers, a phenotype that was enhanced by glutathione chelation and rescued by antioxidant molecules. Mitochondrial membrane potential and contact sites between mitochondria and the ER were reduced in neurons expressing the G392E mutation. These alterations were associated with a pattern of ER stress that involved the ER overload response but not the unfolded protein response. Our results suggest that intracellular accumulation of NS polymers affects the interaction between the ER and mitochondria, causing mitochondrial alterations that contribute to the neuronal degeneration seen in FENIB patients
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